{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-16000 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2026-16000 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-16000 is a high-severity vulnerability in Legion of the Bouncy Castle Inc. bc-csharp, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-16000 and fix it if it is affected.\n\nWhat it is: CVE-2026-16000 is a high-severity vulnerability in Legion of the Bouncy Castle Inc. bc-csharp, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-16000 in the wild and no public exploit code.\n\nAffected product: Legion of the Bouncy Castle Inc. bc-csharp. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-16000/ (Markdown: https://insights.sbomify.com/CVE-2026-16000/index.md)","id":"CVE-2026-16000","markdown":"https://insights.sbomify.com/CVE-2026-16000/index.md","name":"CVE-2026-16000","record":{"aliases":["GHSA-m3jv-gj9x-qwrv"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["data_modify","security_bypass"],"network_reachable":"yes","non_default_config":true,"product_category":"C# cryptography library","requires_auth":"none","summary":"Attackers can forge valid ciphertexts in Bouncy Castle C# when using KCcmBlockCipher without associated data, compromising integrity.","user_interaction":"not_required","vuln_class":"weak_cryptography"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"bcorg","cpe":[{"product":"bc-csharp","vendor":"bouncycastle"}],"cvss":{"score":8.7,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-325","name":"Missing Cryptographic Step"}],"description":"Missing cryptographic step in the DSTU 7624 CCM mode implementation (KCcmBlockCipher) in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows an attacker who can observe encrypted messages of known or chosen content to forge ciphertexts with valid authentication tags, via messages encrypted without associated data. The cause is that the G1 block, which binds the nonce, the message length and the parameter flags into the CBC-MAC, was processed only when associated data was present. Without associated data the tag was a CBC-MAC of the plaintext alone, independent of the nonce. Only applications that use KCcmBlockCipher directly and supply no associated data are affected.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"KCcmBlockCipher (DSTU 7624 CCM) tag not bound to nonce when no associated data is used","id":"CVE-2026-16000","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"weak_cryptography","year":"2026"},"n_packages":0,"n_references":2,"next":{"headline":"IesEngine stream-mode MAC forgery via length-dependent KDF split","id":"CVE-2026-16001"},"packages":[],"prev":{"headline":"AES-CCM decryption accepts zero or out-of-range tag length, bypassing authentication","id":"CVE-2026-15999"},"products":["bc-csharp"],"published":"2026-10-02","related":[{"cvss_score":9.1,"headline":"MTI/A0 DHAgreement does not validate the peer's ephemeral value","id":"CVE-2026-63569","kev_date_added":null,"published":"2026-10-02"},{"cvss_score":8.7,"headline":"Unbounded ASN.1 nesting depth causes process-terminating stack overflow","id":"CVE-2026-103600","kev_date_added":null,"published":"2026-10-02"},{"cvss_score":8.7,"headline":"Unbounded HSS public key level count allows huge array allocation during signature verification","id":"CVE-2026-103603","kev_date_added":null,"published":"2026-10-02"},{"cvss_score":8.7,"headline":"Quadratic-time escaping when converting X.509 distinguished names to strings","id":"CVE-2026-103604","kev_date_added":null,"published":"2026-10-02"},{"cvss_score":8.7,"headline":"DTLS handshake reassembler allocates buffer from unchecked 24-bit length","id":"CVE-2026-63566","kev_date_added":null,"published":"2026-10-02"},{"cvss_score":8.7,"headline":"Unbounded CMP/CRMF password-based MAC iteration count allows CPU exhaustion","id":"CVE-2026-63568","kev_date_added":null,"published":"2026-10-02"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-02","vendors":["Legion of the Bouncy Castle Inc."]},"summary":"Attackers can forge valid ciphertexts in Bouncy Castle C# when using KCcmBlockCipher without associated data, compromising integrity.","url":"https://insights.sbomify.com/CVE-2026-16000/"}